相干MIMO雷达无模糊区面积缩小问题与优化扩展技术研究

在时延-多普勒平面上, 无模糊区面积决定雷达距离模糊与距离杂波折叠特性以及多普勒模糊与多普勒频率混杂特性.文章首次从理论上证明, 采用N个波形的相干多输入多输出(Multiple-Input Multiple-Output, MIMO)雷达存在无模糊多普勒缩小现象, 在一定条件下缩小为单输入-多输出(Single-Input Multi-Output, SIMO)雷达无模糊多普勒的1/N, 导致该雷达无模糊区面积缩小为SIMO雷达的1/N, 并给出了仿真实例.无模糊区面积缩小将导致雷达在杂波环境下性能下降.对此, 提出了将相干MIMO无模糊区面积扩展到与SIMO雷达相等的波形设计技术, 并给出恢复实例, 解决了采用N个频率波形的相干MIMO雷达无模糊区面积缩小的基础性问题.

Unambiguous area reduction problem and expansion techniques of coherent MIMO radar

The unambiguous area in delay-Doppler plane is one of basic parameters of the radar, which determines the unambiguous range, the range-folding, the unambiguous Doppler and the Doppler-frequency aliasing properties. In this paper, for coherent (multiple-input multiple-output MIMO) radar using N frequency waveforms, the unambiguous Doppler is proved to be reduced, and in special conditions to be 1/N of the (Single-input multiple-output SIMO) radar unambiguous Doppler, accordingly, the unambiguous area of coherent MIMO radar is reduced to be 1/N of the SIMO radar unambiguous area. The simulation results display the unambiguous area reduction phenomenon. Furthermore, the paper advances waveforms designing techniques for expanding the unambiguous area of coherent MIMO radar to equal the area of the SIMO radar. The simulation results demonstrate the expansion of the unambiguous area.